LTE technology is described inter alia in Alcatel-Lucent's Strategic White Paper entitled “The LTE Network Architecture—a comprehensive tutorial”, first published as a chapter in LTE . . . From Theory to practice, Wiley 2009.
Spread spectrum techniques are common in cellular communication and include reversible transformation of a signal with a given bandwidth, spreading the signal's energy over a wider bandwidth. The transmitted signal typically has pseudorandom features and can be modulated by a receiver which is configured to generate the same pseudorandom sequence used by the transmitter. In CDMA, plural spread spectrum signals can be transmitted at the same time through the same channel, because they are uncorrelated (orthogonal), hence lack inter-channel interference. Spread spectrum techniques include direct sequence and frequency hopping.
It is possible to generate a set of orthogonal codes (sequence of numbers) e.g. using Hadamard's method for obtaining a set of orthogonal codes.
EBay UK states that “regardless of the type of mobile phone, users can easily connect an external antenna to their phones. Antenna RF ports and antenna accessories are especially common among older cell models, though iPhone and smartphone owners can still take advantage of an instant wireless signal boosts. Fortunately, with a little know-how and the right accessories, connecting an external antenna to a mobile phone is a quick and easy process.Location and Types of RF Ports
Most of the older cell phone models, such as the iconic Motorola RAZR, feature a RF port in the back of the phone that allows users to connect an external antenna. The first step in connecting an antenna to a mobile phone is to check for the RF port. In some Verizon phones, check behind the phone and near the antenna for a small rubber or plastic plug. If the antenna adapter does not fit into the back plug gently, then the RF may be underneath the phone's original antenna.
Another common location of the RF port is along the bottom of the phone. Bottom port connectors typically resemble a charger, and users can find a RF charger combination to boost signal and charge the phone at the same time. Other locations for the RF port include along the top or the side of the phone, or even within the phone's original antenna.
Finding the Right Antenna Adapter for a Mobile Phone
Finding the right antenna adapter for a mobile phone solely can be quite difficult, and it is important to know the phone model number and a corresponding adapter. The location of the RF port also determines the type of mobile phone adapter a user needs. Because the antenna adapter often runs from the RF port to the actual antenna, users should also examine the opposite end of the adapter cable.Most mobile phone adapters feature an FME Male connector opposite the RF connector, and therefore to connect the adapter to an antenna, users need to get an antenna with an FME Female connector. For antennas that have a different connector, users can connect the adapter to the antenna with a FME Female to TNC Female adapter or a FME Female to Mini-UHF Female adapter.. . . Universal Passive Antenna AdaptersAnother option for smartphones that do not have RF ports is the universal passive antenna adapters. These adapters work like a normal antenna, whereas users have to connect the cell phone or signal amplifier to the antenna via a low loss cable. These antenna adapters connect to the back of a phone with a velcro pad. However, passive antenna adapters do not produce the strongest signal, and users often have to include a direct-connect amplifier between the antenna and the adapter in order to achieve a desirable signal.. . . It is always important to . . . consult the phone's user manual to see if a particular external antenna model is compatible”.
A cellphone antenna adapter enables an external cellphone antenna to be connected directly to a cellphone or cellular broadband PC Cards or HotSpot or Routers, thereby improving reception of a variety of phones e.g. Sony Ericsson, Novatel, Sierra Wireless, Pantech, UTStarcom, Audiovox, Nokia, Cingular, Sprint, Kyocera, Samsung, UTStarcom, HTC, LGIC, Motorola, Sony Ericsson, using a cell phone antenna adapter and an external cell phone antenna. On-line manuals explain how to couple, or attach, an antenna to the cellphone. Each PC Card or cellphone antenna adapter typically specifies a connector type e.g. TNC, Mini-UHF or FME which are the connectors that connect to an external antenna of the same type. For instance, a cell phone adapter whose description indicates TNC Female, connects to any antenna with a TNC Male connector. For example, Netgear 778S/779S Hotspot Dual External Antenna Adapter FME/SMA F is an external antenna adapter for Netgear 778S and 779S Mobile Hotspots which has two connectors for both ports on the Netgear Hotspots and two SMA Female connectors to go to two antennas or one MiMo Antenna. An adapter has FME Male connectors and comes with two screw-on SMA Female adapters.
Some smartphones support an external antenna such as:                Palmone Treo 600        Palmone Treo 650        Palm Treo 700w        HP iPAQ h6315        HP iPAQ hw6515) unofficial/unsupported        Cingular 2125, 8125 Pocket PC) unofficial/unsupported        
To connect an external antenna, an appropriate external antenna adapter cable may be used. anamplifier e.g. a Wilson Cellular Dual-Band Inline Amplifier Booster may be used to increase output power.
RIM BlackBerry phones and the Apple iPhone and iPhone 3G may not have antenna ports, but passive inductive antenna adapters are commercially available. Also, a power passive inductive solution, like the Wilson Cellular SignalBoost, can be used.
Modu Mobile is a modular cellular device having the basic functionality of a cellphone e.g. antenna, cellular radio, contact list, text messaging capabilities and a battery, that can be inserted into multiple jackets aka sleeves (such as car stereos, photo frames, car navigation systems, clocks, toasters, laptops, cameras, keyboard, battery, pulse oximeter) that enhance the phone's functionality. By inserting the modular device into various jackets, users personalize their mobile phone's looks and features. The phone is packed with a large memory stick (1 G), that carries over an end-user's personal data (contacts, photos, music), onto other devices, using the jackets. Similarly, Project Ara is an open-source initiative for modular smartphones striving to support third-party hardware development for individual phone components, allowing an end-user to turn to one vendor to upgrade, say, her or his phone's processor, then to another vendor to upgrade the same phone's display.Phonebloks, similarly, work on a concept for making phones modular.
In Project Ara modules are inserted into metal endo-skeletal frames aka “endos”. The frame is a switch to an on-device network linking all modules. Frames of a few different sizes are planned and have slots on the front for the display and other modules and on the back for more modules. Each slot on the frame accepts any module of the correct size. The front slots are of various heights and take up the entire width of the frame. The rear slots have standard sizes (1×1, 1×2 and 2×2). Data from the modules may be transferred at up to 10 gigabits/sec per connection. 2×2 modules have two connections and allow up to 20 gigabits/sec. Thus, these modules provide common smartphone features, such as cameras and speakers, as well as specialized features e.g. medical devices, receipt printers, laser pointers, pico projectors, night vision sensors, or game controller buttons. Modules may be hot-swapped without turning the phone off. Modules were originally to be secured with electro-permanent magnets, but this was replaced by a different method. The enclosures of the modules were planned to be 3D-printed, but instead became a customizable molded case.
Patent document EP2641424A4 to Dov Moran describes a cooperative tablet computer and mobile communicator. Portable telephone sets, e.g. cordless phones, mobile phones or bar type handsets comprise one or a plurality of mechanically detachable modules wherein the modules are operable in the detached state, e.g. one module for the user interface, and one module for the transceiver.
Modu's patent document US20100093401A1 describes a modular wireless communicator including a housing, wireless communication functionality located within the housing, native user interface functionality cooperating with the wireless communication functionality and including user interface surfaces located on at least one outer facing surface of the housing, and pouching responsive electrical interconnection functionality responsive to pouching orientation of the housing in a pouch of an enhanced function device for automatically causing the wireless communication functionality to adapt to interoperation with parenting user interface functionality forming part of the enhanced function device at least partially instead of with the native user interface functionality.
Modu's patent document US20100120468A1 describes a foldable mobile phone.
Modu's patent document WO2009125388A3 describes a modular cell phone for fixed mobile convergence.
“Moving” cellular networks which include at least one relay with both base station and mobile station functionality, are known. Such networks are described e.g. in the following patent documents:
Elta patent document U.S. Pat. No. 9,769,871 to Giloh describes a cellular communication system with moving base stations. Giloh's mobile communication network system comprises a core network including a core device and at least one static base station, base stations, and mobile stations communicating, via antennae, with the base stations. The base stations include at least one moving base station which communicates via antennae with the mobile stations and which has a physical e.g. Ethernet back-connection to a co-located radio manager having a physical connection with a co-located mobile station communicating via antennae with at least one selectable static base station, wherein each individual co-located radio manager comprises a radio resource manager and functionality for receiving information from, and sending information to, other respectively co-located radio managers regarding qualities of their respective connections back to the core network, quality of its own connection back to the core network and channel quality which other base stations are able to provide and which its own base station is able to provide, to mobile stations in the vicinity of the individual co-located radio manager, and for using the information to determine whether to reject at least one mobile station seeking to be served by an individual base station associated with said individual co-located radio manager.
Elta's patent document WO2016071904A1 describes an add-on modem for wireless devices, and a system for ex post facto upgrading of at least one Legacy personal communication device which includes a legacy modem lacking at least one desired wireless communication feature. An auxiliary modem is physically connected via an ex post facto physical connection to a Legacy personal communication device having at least one legacy wireless output channel which has been neutralized or disabled.
Elta's patent document EP2918023A1 describes a partial downlink repeater.
Elta's patent document WO2016199144A1 describes a system for generating, transmitting and receiving auxiliary signals e.g. for use-cases in which portions (“important signal” or “needed signal”) of a signal (“original signal”) are of particular interest in a given situation, but not adequately received in that situation. The method includes generating an auxiliary signal operative e.g. to bridge between imperfect ability/ies of the transmitters in the situation, and specific needs of the receivers in the situation, and/or to improve reception of the important signal and/or important signal information; and transmitting at least the auxiliary signal to the receiving end such that a representation of characteristics of the important signal, comprising the important signal itself and/or important signal information characterizing the important signal, is replaced enhanced or augmented by the auxiliary signal, at the receiving end.
Co-pending patent document EP2643993A1 describes handover initiation methods.
Synchronization based on triangle inequality, in the context of partial downlink repeater apparatus, is described in Patent document US20150270889.
Co-pending patent document WO2012070049A1 describes routing architectures for dynamic multi-hop backhauling cellular networks.
Co-pending patent EP2684395A4 describes a moving cellular communication operative in an emergency mode.
Application of Zadoff-Chu (ZC) sequences to radio signals, yielding an electromagnetic signal of constant amplitude, is known. Cyclically shifted versions of the sequence imposed on a signal then result in zero correlation with one another at the receiver. Cyclically shifted versions of these sequences are mutually orthogonal if each cyclic shift, when viewed within the time domain of the signal, is greater than the combined propagation delay and multi-path delay-spread of that signal between the transmitter and receiver. The auto correlation of a Zadoff-Chu sequence with a cyclically shifted version of itself is generally zero, although it is non-zero at a single instant corresponding to the cyclic shift. ZC sequences are used in LTE (aka the 3GPP LTE Long Term Evolution air interface) in the Primary Synchronization Signal (PSS), random access preamble (PRACH), uplink control channel (PUCCH), uplink traffic channel (PUSCH) and sounding reference signals (SRS). Cross-correlation of simultaneous eNodeB transmissions (hence inter-cell interference) may be reduced by assigning orthogonal Zadoff-Chu sequences to each LTE eNodeB and multiplying their transmissions by their respective codes which uniquely identify each eNodeB transmission.
An alternative to Zadoff-Chu sequences are Walsh-Hadamard codes aka Hadamard code or Walsh code, used in UMTS. These error correcting codes are based on Hadamard matrices. Typically, although not necessarily, Sylvester's construction of Hadamard matrices is used to yield the Hadamard code's codewords.
LTE user equipment (or alternatively LTE device or LTE mobile device) is any equipment or device used by LTE network users to connect to the network and to get services from the network. The user equipment typically has a communication component used to connect to the LTE network—the LTE modem. This modem may be implemented in various ways, such as but not limited to software installed on a CPU and/or DSP, firmware installed on a FPGA, dedicated ASIC (application specific integrated circuit). Examples for user equipment may include: smartphone, mobile phone, tablet, laptop, cellular dongle (small modem card), etc.
The LTE standard defines how user equipment (e.g. typically the LTE modem part of the user equipment) synchronizes itself to the network. Each base station periodically transmits standard PSS and SSS signals that are used by the user equipment to synchronize itself to the network and extract needed system information that these signals carry. After appropriately receiving the PSS and SSS, the user equipment can synchronize itself to the network and get the information required for upcoming operations in the process of the connection to the network. The LTE standard does not prevent any LTE mobile device (e.g. LTE modem) to synchronize itself to an LTE network. On the contrary, the LTE network invites any LTE user equipment to camp on it (to join the network and get services). This is done by broadcasting the standard PSS and SSS synchronization signals and other vital network's information.
This initial LTE system information (network information of base-station specific information) is broadcasted without any security measures because of the desire to function as an “open” network which allows all LTE modems to synchronize and get basic information about the network so each modem will know if it wishes to connect to that network. For example, this system information contains typically the MIB—Master Information Block and optionally also some of the SIBs—System Information Blocks, which are used e.g. are necessary for user equipment to establish its initial connection to the network. Typically, only by having part of or all this information, conventional user equipment can synchronize and tune itself to the network. The security and authentication mechanisms, which have been defined by the LTE standard, are not operated at this stage. The LTE user equipment can synchronize itself to the network and unveil network Master/System Information Blocks and then, if it wishes, try to continue the process of registration and getting services from the network. However, in private LTE network (aka a network that wants to be detected and give services only to a specific group of LTE user equipment and not to be able to be detected by any other LTE user equipment), this feature that enables every user to synchronize to the network and therefore to detect the network and get access to its system information and try to get services from the network, is not desirable and it may be desired to overcome this. alternatively or in addition, in standard LTE network and more specifically in private LTE networks, this “open” network feature can be also a security vulnerability that may allow DoS (Denial of Service) attacks and therefore again, overcoming this may be desirable.
PSS and SSS are two types of synchronization signals—primary and secondary. Both are detected by all types of UE and are transmitted twice per 10 ms radio frame, or every 5 ms. In LTE, the synch signals are fixed at the central 62 subcarriers of the channel, so the cell search procedure is the same for all types of bandwidths. In LTE, 72 subcarriers (6 RB) are available, but only 62 are used so that UE may perform the cell search using an efficient length of 64 FFT. Primary synch signals are modulated with frequency domain Zadoff-Chu sequence, since Zadoff-Chu may provide lower PAPR than OFDM does. PSS is used for cell identity, whereas SSS is used to identify cell-identity groups. The number and position of subcarriers for SSS, as for the primary synch signal, are the central 62 subcarriers. In cell search, PSS is used first. The UE determines the timing and center frequency by detecting the primary synch signal.
The LTE standard defines how user equipment synchronizes itself to the network. Each base station transmits standard PSS and SSS signals which the user entity, aka user equipment, aka UE, may employ to synchronize itself to the network and to extract the specific system information that these signals may carry which may be used for upcoming stages of connection to the network. The LTE, as a standard, does not prevent any LTE device to synchronize itself to an LTE network. On the contrary, the LTE network invites any LTE user equipment to camp on it, by broadcasting the standard PSS and SSS synchronization signals and vital information required by user entities to camp on the network (the MIB—Master Information Block and SIBs—System Information Blocks, necessary for every user device to establish connection to the network, synchronize and tune itself to the network), without any security constraints. The security and authentication functionalities defined by the 3GPP do not, according to the standard, operate at the above stage. The LTE user equipment may synchronize itself and unveil network System Information Blocks (SIBs), and try to obtain access to it.
The disclosures of all publications and patent documents mentioned in the specification, and of the publications and patent documents cited therein directly or indirectly, are hereby incorporated by reference.